Hot pixel removal

[TrevorAustin]

I’ve just changed to a 585 based camera and want to get rid of the boredom of shooting darks.

On reading various posts the recommendation seems to be to use hot pixel removal and flats and flat darks.

However when I got to take dark flats it won’t let me because it sees hot pixel removal as dark subtraction.

Have I misunderstood or should I turn off hot pixel removal and then do the flats and flat darks and turn it back on afterwards?

[admin]

Hi,

when you are creating a master flat frame (ie flat minus dark flat or flat minus bias), you are generally working at short exposures, which limit the impact of hot/warm pixels significantly. Not only that, but because the data used for the actual flat correction has the subtraction of the bias/dark flat, the hot/warm pixels tend to cancel out between the two, meaning that the do not influence the flat frame. The exception to that would be relatively long exposure flat captures (say >1s) with bias frames, but the best practice is to use dark flats for relatively long exposures anyway.

The upshot of this is that you don't need to worry about hot pixels when taking flats as they are pretty much automatically dealt with, so turn it off before capturing flats.

I am now wondering however if I just need to tweak the flat capture code to be aware of hot/cold pixel removal as not being 'proper' darks... I will investigate.

cheers,

Robin

[TrevorAustin]

Thank you, or maybe just set capturing to automatically turn off any darks setting?